A face is just a face. It's what you do with it that makes the difference.
I've known a great many people, myself included, that weren't exactly blessed with nice friendly looking features. But, I can tell you from personal experience that what you look like doesn't have much to do with whether people perceive you as fierce, or intimidating.
To give an easy example, let's take it to extremes. I've known some 1% bikers. Real actual gang members. Who went well out of there way to augment their appearance to appear more intimidating. Tattoos, leather, poor choices in facial hair, the whole thing... But when you actually got to talking to a lot of these guys, they were teddy bears. Sure they could put on the scary biker thing, but when it came down to it, they were good guys. Loyal, friendly, and quick with a joke or a laugh. To be clear, these weren't weekend warriors, they weren't faking it, some of these guys knew where the bodies were buried because they put them there.
But... They were still human... Perhaps horrifically flawed and potentially violent humans, but still just humans.
Being well and truly intimidating is usually deliberate. Most people aren't going to be intimidated by the way your face looks. It's more in your mannerisms, the way you carry yourself. You can look like a murderer, hell you can be an actual murderer, and not be perceived that way by changing your attitude. And in changing your attitude, you end up changing the way you carry yourself.
If you're tense and guarded, you'll look tense and guarded. If you're volitile, you'll look volitile... If you're self conscious... You'll look self conscious. But if you're relaxed and open to getting to know people, that shows too.
My point is, putting on an intimidating face doesn't tend to work, neither does putting on a happy face. You're fighting against a social evolution that's been happening since before humans were humans. Before we had language we had to be able to read each other's faces to determine if the other ape was friendly or going to eat us.
If you really want to look more approachable, work on feeling more approachable.